Net wrapping method

ABSTRACT

A method of wrapping cylindrical bales of crop material with netting material for use with apparatus including a feed roller which may be selectively driven to dispense the netting material from a supply roll into a round baler. The apparatus has a home position and a cutting position wherein the feed roller is latched. The apparatus also has a feeding position wherein the feed roller is driven. The method includes the steps of latching the feed roller when the apparatus is in the home position, unlatching the feed roller when the apparatus is moved from the home position to the feeding position, relatching the feed roller when the apparatus is moved from the feeding position to the cutting position, and maintaining the feed roller latched as the apparatus is moved from the cutting position to the home position.

BACKGROUND OF THE INVENTION

This invention relates generally to round balers for making cylindricalbales of crop material and, in particular, to an inproved net wrappingmethod for such balers.

U.S. Pat. No. 4,768,431 granted Sept. 6, 1988 to John H. Merritt III etal. discloses a net dispenser drive for round balers wherein a net feedroll is latched as a knife is moved into an operative position to cutthe netting material. This latching of the feed roll exerts extra forceon the netting material causing it to be cut by the knife. After thenetting material is cut, the knife is moved into a retracted positionwhich simultaneously causes unlatching of the feed roll. With the feedroll unlatched, netting material is sometimes fed into the baler atimproper times. Furthermore, when the feed roll is unlatched, nettingmaterial could hang on incoming crop material during bale formation andbe inadvertently fed into the baler.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improved netwrapping method for round balers which overcomes the above-mentionedproblems.

It is a further object of the present invention to provide a netwrapping method for round balers wherein the timing of the latching andunlatching of a net feed roller is improved thereby resulting in morereliable cutting of netting material and reduced wear on the mechanismthat latches and unlatches the feed roller.

The present invention accomplishes these objects by providing a netwrapping method for use with apparatus including a feed roller which maybe selectively driven to dispense netting material from a supply roll.The apparatus has a home position and a cutting position wherein thefeed roller is latched. The apparatus also has a feeding positionwherein the feed roller is driven. The method comprises the steps oflatching the feed roller when the apparatus is in the home position,unlatching the feed roller only when the apparatus is moved from thehome position to the feeding position, relatching the feed roller whenthe apparatus is moved from the feeding position to the cuttingposition, and maintaining the feed roller latched as the apparatus ismoved from the cutting position to the home position.

In its preferred embodiment, the method may also comprise the steps ofmoving a knife connected to a lever from a retracted position into anoperative position when the apparatus is moved from the feeding positionto the cutting position, and maintaining the knife in the retractedposition when the apparatus is in the home and feeding positions. Themethod may further comprise the steps of extending a piston of anactuator connected to the lever to rotate the lever in a first directionand thereby move the apparatus from the home position to the feedingposition, retracting the piston to rotate the lever in a second oppositedirection and thereby move the apparatus from the feeding position tothe cutting position, and partially extending the piston to rotate thelever in the first direction and thereby move the apparatus from thecutting position to the home position.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation view of a round baler incorporating animproved net wrapping method according to the present invention;

FIG. 2 is an enlarged side elevation view of the net wrapping apparatusshown in FIG. 1 in a home or bale forming position;

FIG. 3 is a further enlarged sectional view taken along lines 3--3 inFIG. 2;

FIG. 4 is an enlarged side elevation view similar to FIG. 2 with the netwrapping apparatus in a feeding position; and

FIG. 5 is an enlarged side elevation view similar to FIG. 2 with the netwrapping apparatus in a cutting position.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, a round baler 10 generally of the type disclosed inU.S. Pat. No. 4,426,833 includes a main frame 12 supported by a pair ofwheels 14, a tailgate 16 pivotally connected to the main frame 12, apickup 18 pivotally mounted on main frame 12 and supported by a pair ofwheels 20. A bale forming apron 22 extends around guide rollers 24 thatare rotatably mounted in the main frame 12 and in the tailgate 16. Roundbaler 10 also includes a tongue 26 for attachment to a tractor (notshown) so that the round baler 10 may be towed across a field to pick upcrop material and form it into cylindrical bales.

A supply roll 28 of netting material N is mounted on a spindle 30rotatably journalled in the main frame 12 in a manner such as disclosedin U.S. Pat. No. 4,768,431 granted Sept. 6, 1988 and incorporated hereinby reference. Net wrapping apparatus 32 is provided to feed nettingmaterial N from the roll 28 so that it may be wrapped circumferentiallyaround bales formed in the round baler 10. Apparatus 32 also serves tocut the netting material once the formed bales have been sufficientlywrapped with approximately 1-2 full revolutions of netting material.Drive means 34 is connected to a feed roller 36 which is part of theapparatus 32 to provide power to the feed roller 36. Power for drivemeans 34 is supplied by a chain 38 which extends around a sprocket 40that is driven from a shaft 27 coupled to the PTO of a tractor. Chain 38is tensioned by a spring loaded idler 42.

As seen in FIG. 2, apparatus 32 includes the feed roller 36 and a pairof pinch rollers 44, 46 mounted on opposite sides of the feed roller 36.The netting material N extends from the roll 28 under the pinch roller44, then upwardly between the pinch roller 44 and the feed roller 36,over the feed roller 36, and then downwardly between the feed roller 36and the pinch roller 46. A complete description of the manner in whichthe feed roller 36 and the pinch rollers 44,46 are mounted is disclosedin U.S. Pat. No. 4,790,125 granted Dec. 13, 1988 and incorporated hereinby reference. Drive means 34 includes a double sprocket 48 driven bychain 38, another chain 50 connected between double sprocket 48 and asprocket 52, a pulley 54 fixed to the sprocket 52, and a belt 56extending around the pulley 54 and another pulley 58 which is mounted ona shaft 37 of the feed roller 36.

An electrical actuator 60 is pivotally connected at one end to a bracket62 mounted on the main frame 12. The other end of the electricalactuator 60 has a piston 61 pivoted to a lever 64 which is rotatablymounted on the feed roller shaft 37. An idler pulley 66 is carried onthe lower end of the lever 64 for engagement with the belt 56. When thelever 64 and the idler pulley 66 are positioned as shown in FIG. 2, thebelt 56 is slackened and no driving power is delivered to the feedroller 36. A rod 68 is carried on the upper end of the lever 64 andextends through a plate 70. A latch arm 72 is rotatably mounted on ashaft 74 which is supported by a bracket 76 bolted to the main frame 12.Plate 70 is fixed to the latch arm 72 for rotational movement therewith.Latch arm 72 has a notch 78 engageable with a key 80 on the feed roller36 for preventing rotation of the feed roller 36. A compression spring82 on the shaft 74 provides a frictional mounting arrangement for thelatch arm 72.

Referring to FIGS. 2, 4 and 5, a bracket 84 fixed to the lever 64 ispivotally connected to a link 86 which has a slot 88 engaged with a pin90 extending from another link 92. A knife 94 is carried by the link 92,and both the knife 94 and link 92 are rotatably mounted on a shaft 96.Knife 94 is movable between a retracted position shown in FIG. 4 and anoperative position shown in FIG. 5. A spring 98 connected to link 92normally urges the knife 94 into the retracted position.

In operation, net wrapping apparatus 32 is in a home or bale formingposition illustrated in FIG. 2 during formation of a bale in the roundbaler 10. With apparatus 32 in this home position, the feed roller 36 islatched by engagement of the notch 78 in the latch arm 72 with the key80 on the feed roller 36. This latching of the feed roller 36 preventsimproper feeding of the netting material N. Also, in the home positionof the apparatus 32, the knife 94 is retracted. When a bale has beenformed in the round baler 10 and is ready to be wrapped, the electricalactuator 60 is operated to extend the piston 61 thereby rotating thelever 64 in a clockwise direction on the shaft 37 until the apparatus 32is moved from its home position of FIG. 2 into a feeding positionillustrated in FIG. 4.

Initial clockwise rotation of the lever 64 causes rod 68 carried on theupper end thereof to be pulled through plate 70 until a cap nut 69 onthe rod 68 engages the plate 70. Further clockwise rotation of lever 64results in rod 68 rotating the latch arm 72 away from the feed roller 36so that the notch 78 therein is disengaged from the key 80 on the feedroller 36. The feed roller 36 is unlatched. This further rotation of thelever 64 also moves the idler pulley 66 carried on the lower end thereofinto engagement with the belt 56, thereby tightening the belt 56.Driving power is delivered from the pulley 54 to the pulley 58 via thebelt 56, and the feed roller 36 is driven to dispense netting material Nfrom the roll 28 into the round baler 10 where it is wrappedcircumferentially around a bale. The aforementioned clockwise rotationof the lever 64 does not, however, cause any movement of the knife 94due to the lost motion connection between the pin 90 on the link 92 andthe slot 88 in the link 86.

Once the bale has been wrapped with approximately 1-2 full revolutionsof netting material, the electrical actuator 60 is operated to retractthe piston 61 and thus rotate the lever 64 in a counterclockwisedirection so that the pulley 66 is disengaged from the belt 56. Thiscauses slackening of the belt 56 which stops driving power from beingdelivered to the pulley 58 connected with the feed roller 36. Theinitial couterclockwise rotation of the lever 64 also causes the rod 68to be pulled through plate 70 until nut 71 on the rod 68 engages theplate 70. Further couterclockwise rotation of the lever 64 results inrod 68 rotating latch arm 72 toward the feed roller 36 so that the notch78 therein is engaged with the key 80 on the feed roller 36. Thisrelatches the feed roller 36. The afore-mentioned couterclockwiserotation of the lever 64 also causes movement of the knife 94 into itsoperative position to severe the netting meterial N. The apparatus 32 isnow moved to its cutting position shown in FIG. 5. The latching of thefeed roller 36 increases the tension on the netting meterial N so thatit is easily cut by the knife 94.

After the netting material has been cut, the electrical actuator 60 isoperated again to partially extend the piston 61 causing clockwiserotation of the lever 64 and thereby moving the apparatus 32 from thecutting position of FIG. 5 to the home position of FIG. 2. The feedroller 32 remains latched by the latch arm 72, and the knife 94 isreturned to its retracted position. Subsequently, the tailgate 16 isopened and the net wrapped bale is discharged from the round baler 10.The round baler 10 is now ready to form and wrap another bale.

What is claimed is:
 1. In a round baler for making cylindrical bales ofcrop material having apparatus for wrapping said bales with nettingmaterial, said apparatus including a knife and a feed roller which maybe selectively driven to dispense netting material from a supply rollinto said round baler, said apparatus having a home position whereinsaid feed roller is latched and said knife is retracted and a cuttingposition wherein said feed roller is latched and said knife is actuated,said apparatus also having a feeding position wherein said feed rolleris driven, a method comprising the steps of:latching said feed rollerwhen said apparatus is in said home position; unlatching said feedroller when said apparatus is moved from said home position to saidfeeding position; relatching said feed roller when said apparatus ismoved from said feeding position to said cutting position; maintainingsaid feed roller latched as said apparatus is moved from said cuttingposition to said home position; moving said knife which is connected toa lever from a retracted position into an operative position when saidapparatus is moved from said feeding position to said cutting position;maintaining said knife in said retracted position when said apparatus isin said home and feeding positions; extending a piston of an actuatorconnected to said lever to rotate said lever in a first direction andthereby move said apparatus from said home position to said feedingposition; retracting said piston to rotate said lever in a secondopposite direction and thereby move said apparatus from said feedingposition to said cutting position; and partially extending said pistonto rotate said lever in said first direction and thereby move saidapparatus from said cutting position to said home position.
 2. In around baler for making cylindrical bales of crop material havingapparatus for wrapping said bales with netting material, said apparatusincluding a knife and a feed roller which may be selectively driven todispense netting material from a supply roll into said round baler, saidapparatus having a home position wherein said feed roller is latched andsaid knife is retracted and a cutting position wherein said feed rolleris latched and said knife is actuated, said apparatus also having afeeding position wherein said feed roller is driven, a method comprisingthe steps of:latching said feed roller when said apparatus is in saidhome position; unlatching said feed roller when said apparatus is movedfrom said home position to said feeding position; relatching said feedroller when said apparatus is moved from said feeding position to saidcutting position; maintaining said feed roller latched as said apparatusis moved from said cutting position to said home position; and saidlatching and relatching steps including moving a latch arm toward saidfeed roller into engagement with said feed roller, and said unlatchingstep including moving said latch arm away from said feed roller out ofengagement with said feed roller.